Sister Dr. Mona Tyndall (14 April 1921 – 7 June 2000) was a medical doctor and Roman Catholic missionary in Nigeria and Zambia. She was one of the six children of businessman David P. Tyndall and his wife, Sarah Gaynor Tyndall. Raised in County Dublin, she became a member of the Roman Catholic religious congregation of the Missionary Sisters of the Holy Rosary (MSHR). A missionary in Nigeria and Zambia, she was an active development worker in the early fight against HIV/AIDS through her leadership of Mother & Child Clinics which were supported by the Irish Government's overseas aid programme in Zambia. Religious profession & medical qualifications She joined the Holy Rosary Sisters in Killeshandra, County Cavan, in 1940, and after religious profession on 28 August 1942, she later qualified as a medical doctor at University College Dublin. She then went to England and qualified as an obstetrician and gynaecologist. Missionary life Nigeria and the Biafran War She began her missionary life in Africa starting in Nigeria in 1949 where she ministered to the sick and particularly to young mothers. She was very active along with her fellow religious, in caring for the wounded and displaced during the Biafran War which broke out in Nigeria in 1967. Mission hospitals and feeding centers were overwhelmed by the plight of the sick and wounded civilians and soldiers, and she labored to save lives and console homeless orphans. She and others cared for the starving and the dying. Federal Nigerian troops overcame the Biafran secessionist resistance, and took possession of all the Mission stations. Sister Mona and her fellow sisters and priests remained at their posts as long as they could until they were arrested and imprisoned, along with their Bishop, Dr. J. Whelan, C.S.Sp. They were reportedly released only through the personal intercession of Pope Paul VI and then deported from Nigeria. Zambia The remainder of her missionary life was spent in Zambia, where she worked firstly in Monze Mission Hospital, and later in Lusaka University Teaching Hospital (UTH), after a brief year in the Westminster Pastoral Institute in London. As Consultant Obstetrician/Gynaecologist at Lusaka UTH, she became a national tutor in the sympto-thermal method of family planning. Concerned with hospital overcrowding and high post-natal mortality, she strove to reduce maternal mortality by half in the 1990s, in accordance with the "Health for All" Alma Ata Declaration (1978). In this, she was